Block-signal system.



T. BODDE.

BLOCK SIGNAL SYSTEM.

APPLICATION FILED SEPT. 19,-1907.

1 ,IGQBSO. Patented Dec. 14, 1915.

Flai.

THEODORE BODDE, OF WESTFIELD, NEW JERSEY, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO HALL SWITCH & SIGNAL COMPANY, OF NEW YORK, N. Y., A

CORPORATION OF MAINE.

BLOCK-SIGNAL SYSTEM.

Application filed September 19, 1907.

To all whom it may concern:

Be it known that I, Trrnooonn Bonon, a subject of the Queen of Holland, residing in Westfield, in the county of Union and State of New Jersey, have invented a certain new and useful Improvement in Block-Signal Systems, of which the following is a true and exact description, reference being had to the accompanying drawings, which form a part thereof.

The present invention relates to automatic electrically controlled block signal systems for railways in which the track rails are electrically continuous and form parts of electric power circuits.

The object of the present invention is the provision of simple and effective apparatus which will denote the presence of a train or a broken rail in any block and actuate suitable signals at the block ends accordingly; which will not be influenced by the power current flowing along the track rails; and which will not require any interference, or at least any material interference, with the track rails as conductors of the power cur rent.

In carrying out my invention I utilize as the sources of the signaling current two sources of alternating current, which may be of the same electromotive forces but which are of different frequency, and are, if the power current is alternating, each of a frequency materially different from that of the power current. I connect the source of one frequency between the track rails of alternate sections and the source of the other frequency between the track rails of the intermediate sections, the connection to each.

section being made at points preferably remote from each end of the section. At the common ends of each adjacent pair of track sections I connect the track rails by a conducting cross bond and employ in conjunction with such cross bonds selective signal controlling devices each of which will re- Specification of Letters Patent.

Patented Dec. 1 1, 1915.

Serial No. 393,640.

shunt with a bridge offering but slight impedance to the power circuit but appreciable resistance to the signal circuit. I have also devised means by which I may effectively impress 011 the terminals of such a bridge an electromotive force of such a frequency, intensity and direction as to materially limit or prevent a flow of current through the bridge from the source of signaling current connected between the track rails of the section ahead.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, reference may be had to the acco1npanying drawings and descriptive matter in which I have illustrated and described forms in which my invention may be embodied.

Inthe drawings, Figure 1 is a diagrammatic representation of a system embodying one form of my invention. Fig. 2 is a diagram representing a modification of a por tion of the system shown in Fig. 1. Fig. 3 is a modification along the lines of Fig. 2 for use on single track railway signal systems. Fig. 4 is a diagram representing a system different in some respects from that of Fig. 1, and Fig. 5 is a diagram showing a modification of the system of Fig. 4. for single track purposes.

In the drawings, and referring first to Fig. 1, A represents the two alinin sets of rails forming one railway track. 'fhe rails in alinement are electrically connected together, but are divided into sections 1, 2, 3, etc, at the points 1 2, 2-3, etc, by the conducting track bonds B B etc. Each of the sections is supplied with alternating current as by the secondaries of the transformers C, C and C, which are connected between the two track rails of the corresponding section at points remote from the ends of the section and preferably midway between the ends of the sections. Resistances a are inserted in the transformer connections for the purpose of avoiding too great current variations when the transformers are short circuited by trains on the track rails. The primaries of successive transformers C", C G etc., are connected alternately to supply conductors D and E The conductors E are supplied with alter nating current from a source of one frequency, say eighty, and the conductors D from a source of alternating current of another frequency, say one hundred and twenty. The circuits D and E may be as shown, or in any equivalent relation to each other. The cross bonds B B etcl, need have only. a small amount of reactance, and

form ready paths for the currents from the transformers C, C G etc. In Fig. 1, the bonds B B etc., form the primaries of the transformers, the secondary windings F F of which energize the stationary members Gr, H G H of the selective signal controlling instruments or relays. The

movable coils I, J P, J are in inductive are connected to sources of alternating cur-j rent of the same'frequency as that supplied to the corresponding block sections. In practice, as shown in the diagram, the coils I, J I J are connected across the lines D and E. Each of the coils 1, J I J etc., carries a contact arm K, and each coil is so arranged that when not operatively actuated by the corresponding stationary member the contact Kextends horizontally, but when the coils are operatively actuated they extend in the inclined direction shown in Fig. l.

controlling circuits L, L L etc. It will be understood that the coil I for instance will only be operatively actuated by the member G when current flows through the winding of the latter of the frequency supplied to the coil I, c'. 0. when current flows through bond B from transformer C. It

' will also be understood by those skilled in the art that when current flows through the bond B from transformer C, coil 1 will respond even though current flows through bond B from transformer C at the same time. It is evident'tha't members G and'I-I may be arranged as shown, or in any equivalent manner, and that the selective devices or relays shown may be readily replaced by other kinds of known selective instruments.

-The signals actuated and controlled by the circuits L, L L etc., may be any of the usual types and be operated according to any of the known arrangements.

In the arrangement shown in Fig. 1, for the purpose of illustration only, the circuits L, L and L run between the signal stations at the ends of the sections 1, 2, 3, etc. With signals at the ends of each section,

The contact arms K when in the inclined position close signal actuating or each section forms a block. At each signal station there is a home signal, a distant signal, a battery and certain local circuits and signal controlling devices. Each of the signal circuits L, Lfland L" has a gap at each of the stations which it connects which is closed only when the corresponding pairs of coils I and J, I and J I and J, etc, hold their contact arms K in the inclined position. I

I will now describe the operation of the devices at one of the stations, say, the station 1 2. The circuit L includes a relay M at station 12 and the battery 0 at station 23. hen the circuit L is energized, relay M attracts its armature M and closes a circuit through battery 0 and the actuating devices S for the home signal S at station 12. This brings the home signal S into the inclined or clear position shown in Fig. 1. Signal S when in this position bridges gaps in the distant signal controlling circuits Q. and Q running to the left and right hand adjacent stations respec tively. The circuit Q} also includes the battery at station 23 and is broken at that station except when the signal S there is in the clear position. The circuit Q also includes the relay N, which when energized attracts its armature N and closes a circuit through the battery 0 and the energizing device T of the distant signal T at station 12.

It will thus be observed that the circuit L for instance can only be closed when the coils J and I are both in the inclined position, and these coils will be in this position only when. the block 2 is free from trains, and there is no break in any of the track rails, since it is only then that an appreciable cur rent of the proper frequency passes through the windings of the stationary members H and G The signal S at station ].-2 can therefore be brought to clear only when the block 2 is free from trains and the tack rails are unbroken. As the distant signal T for instance at station 1-2 is controlled b v circuit Q and the latter is closed only when the home signals S at station l2 and station 23 are both in the clear position, it is only when these two home signals are in the clear position that the distant signal T can be brought to the clear position.

Should there be a train on the track rails A in Fig. 1 which moving in the direction of the arrow has reached a point closely adjacent the cross bond B-, for instance, it is apparent that the train will serve as a bridge about the cross bond B not only for the current from the transformer C but also from the transformer C since the cross bond B offers some though slight impedance to the signal current from transformer C This, if not otherwise counteracted, would 5::

I coil is in the inclined position.

require that the signals S and T at station 1-2 should be moved to the left'of the cross bond B a small distance, say twenty or thirty feet. Such a method of correction, however, is not in all respects satisfactory, especially as the distance which the signal should be displaced is a variable one. To avoid this difficulty I have devised the ar rangementshown in Fig. in which a cut T is formed in one of the rails A immediately to the left of each of the cross bonds. This cut I bridge by a conductor V of slight re sistance to the power current but offering an appreciable impedance to the signal currents. With this arrangement there is a great diminution of the current from the transformer C diverted from the cross bond B by a train at any point closely adjacent the left of the cut U. With the bridges V the gap U does not need to be in the form of an elaborate or high resistance insulated rail cut. A very little insulation will do, especially as a fault in the insulation will merely result in giving a false danger signal.

lVhere the signal system is for use on a single track railway, I may. as shown in Fig. 3, divide the inductive resistance, bridging the cut U into two equal parts V, V, and connect the cross track bond B into the middle of the inductive resistance. If the inductive resistance V, or each of the inductive resistances V, is approximately equal to the inductance of the winding 13 (and it need not be greater) the latter will at least half of the signal current which ought to come to it normally from one of the sources no matter how close a train may be to theend of the block.

In Fig. 4., I have shown an arrangement in which the inductive resistances V around the cuts U at the leaving end of each block are in inductive relation with windings etc. Each of the windings W, etc, is in circuit with the secondary of the proper one of the transfori'ners X etc.. the primary of which is supplied with alternating current of the frequency supplied to the section at the right of the cut U. By this arrangement an electro-motive force is applied to the ends of the rail cut at U, at station l2 for instance. which may be made equal and opposite to the electro-motive force between the two rails at the end 12 of the section 2, so that wandering of the signal current beyond the end of the block is positively prevented while at the same time a minimum resistance to the passage of the power current along the rails is obtained.

To prevent false signal indications the connections between each pair of trasformers X and Vi, V and WV, V", etc, includes a gap bridged by the contact arm K of the corresponding coil J J etc, when the As a result of this arrangement, current will not be sent through the cross bond at section end 12 for instance from transformerl v V when there is a train to the left but close to the cut U unless the coil J is already in the inclined position corresponding to a clear track with unbroken rails between station 1-2 and the points of connection of the transformer C With the means shown in Fig. 4 for impressing an electromotive force between points on one of the track rails at one side of the adj accnt cross bond to prevent current flow from the t'ansformer of the section at the other side of the bond. it is not necessary to make the reactance of the cross bonds particularly small. These cross bonds. therefore, may include the winding of the corresponding selective relays, as shown, in Fig. 4. Fig. L also illustrates the fact that the coils I, J, P, J etc., may be connected to the lines I) and it through transformers Z, X Z X etc, instead of directly asin Fig. 1.

Fig. 5 illustrates the utilization of the counter electromotive force means for preventing wandering of the signal currents from their appropriate sections in a single track railway with train movements in both directions. The arrangement of Fig. 5 differs from that of Fig. 4 in that the cross bond between sections 1 and 2 is connected at one side into the middle of the bridge V and that the primary W is divided into two sections. One of these sections is supplied with current from lines D and the other with current from the lines E. The connections for each half of winding includes a gap bridged by the proper contact K only when the corresponding coil 1, etc., or J etc, is in the inclined position.

The system disclosed gives adequate protection in a simple and eflicient manner with apparatus which is comparatively simple and inexpensive in construction and in which the use of the track rails as a part of a power circuit is interfered with only to a very slight extent if at all. By connecting each transformer between the track rails at points approximately midway be tween the ends of its section the length of track rails from each transformer to each cooperative cross bond at either end of the sections becomes one thirdthe length of track rails between that transformer and the cross bonds at the ends of the alternate sections supplied with current of the same frequency. This effectively prevents the selective instrument of one frequency operating in conjunction with one cross bond from being affected by the current from a remo e transformer of the same frequency. A train adjacent a cross bond and the track rail portions between the train and the bond form a shunt for the bond tending to divert current therefrom supplied from the signal supply source at the other side of the bond. The impedance in such a shunt to such a diversion of current which is formed by such arrangements as the simple inductive resistnecessary for this purpose need not be large,

since it cooperates with the natural impedance of the track rail portions between the cross bond and the train adjacent thereto.

lVhile in accordance with the requirements of statutes I have described the best forms of my invention now known to me, it will be understood by those skilled in the art that many changes may be made in the forms in which my invention is embodied without departing from the spirit of my invention. In particular, it is one of the ad-i vantages of my invention that in installing it much of the apparatus heretofore installed may be used.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a block signal system for railways having electrically continuous track rails, the combination with the track rails of conducting cross bonds connecting the rails at intervals and dividing them into sections, a source of alternating current connected between the track rails of each section and at a distance from each end thereof, the sources connected to adjacent sections being of different frequencies, and a pair of selective signal controlling devices in conjunction with each cross bond, one of said devices responding to a current flow through the bond of the frequency supplied to one of the adjacent sections and the other to current of the frequency supplied to the other of the adjacent sections, and neither responding to currents of both frequencies.

2. In a block signal system for railways having electrically continuous track rails, the combination With the track rails of conducting cross bonds connecting the rails at intervals to divide them into sections, a source of alternating current connected between the track rails of each section and at a distance from each end thereof, the sources connected to adjacent sections being of different frequencies and the sources connected to alternate sections being of the same fre quency, and a pair of selective signal con-- trolling devices in conjunction with each cross bond, one of said devices responding to a current flow through the bond of the frequency supplied to one of the adjacent sections and the other to current of the frequency supplied to the other of the adjacent sections, and neither responding to currents of both frequencies.

3. In a block signal system for railways having each alining set of track rails electrically connected together, cross bonds connected between the two sets of rails at intervals to divide them into sections, a series of transformers, one for each section, each transformer having its secondary connected between the rails of its section at a distance from the ends of the section, the primaries of alternative t 'ansformers being connected to a source of alternating current of one frequency, and the primaries of the intervening transformers being connected to a source of alternating current of a different frequency, and a pair of selective relays in conjunction with each cross bond, one relay responding to a current flow through the bond of one of said frequencies and the other to a current flow through the bond of the other frequency.

4:. A tratlic controlling system comprising conductively continuous rails, section limiting conductors connected across said rails at intervals, coils in inductive relation to said conductors, means for producing in the sections a difference of potential between the rails, and trafiic controlling apparatus controlled by said coils.

5. A railway traflic-controlling or signaling system comprising successive sections of a railway track said track having rails conductively continuous and of uniform impedance electrically controllable traiiiccontrolling or signaling means in control of traffic along said track, and successively adj acent track circuits in control of the trafficcontrolling or signaling means and including the rails of successively adjacent sections of the track and including cross-bonds from rail to rail at the adjacent ends of adjacent track sections and having such a low relative impedance as to substantially limit the currents of the track circuits to their respective track sections and constituting the primary conductors of transformers, and secondaries arranged to supply controlling current to the signaling or traflic-controlling means.

'6. A railway traffic-controlling or signaling system comprising successive sections of a railway track said track having rails conductively continuous and of uniform impedance electrically controllable traiiiccontrolling or signaling means in control of traffic along said track, a track circuit including the rails of a section of the track and including a bonding conductor in a single length leading direct from ail to rail at the end of the section, and a coil in control of the trafiic-controlling or signaling means placed in inductiv'e relation to the bonding conductor and adapted to receive therefrom the electrical energy which con- .l on

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trols the signaling or traiiic controlling means.

7. A railway traffic-controlling or signaling system comprising successive sections of a railway track said track having rails conductively continuous and of uniform impedance electrically controllable tratlic-controlling or signaling means in control of traflic along said track, sources of current connected to the opposite rails and each feeding the rails in both directions, bonding conductors in single lengths cross-bonding the rails at points between the sources, and coils in control of the signaling or trafficcontrolling means and placed in inductive relation to the bonding conductors and adapted to receive therefrom the electrical energy which controls the signaling or tralfic-controlling means.

8. A railway trafiic-controlling or signaling system comprising successive sections of a railway track, said track having rails conductively continuous and of uniform impedance, electrically controllable signaling or trafliocontrolling means in control of traffic along said track, and a controlling electric track circuit in control of the signaling or traliic-controlling means and including the rails of a section of the track and including a cross-bond between said rails substantially at the end of the section and having such a low relative impedance as to substantially limit the current of'said track circuit to its said section and also constituting the primary conductor 01": a transformer and a secondary connected to the signaling or trafficcontrolling means to convey controlling current thereto.

F. K. l/VINTER.

Eopiea of thia patent may be obtained for five cents each, by addressing the "Commissioner of Patents.

Washington, D. G. 

